Subsidence in Maceio, Brazil, Characterized by Dinsar and Inverse Modeling

Abstract

The city of Maceió has been historically affected by cracks and sink events in buildings and city infrastructure. Availability of a consistent Sentinel 1 Mission dataset between 2014 and 2019 allows characterizing the undergoing crustal deformation process that provokes such effects. We processed a dataset of 81 SAR scenes using the DInSAR-SBAS time-series technique, which allowed us to obtain mean velocity of deformation and deformation time series. Detected displacement patterns show subsidence concentrated in the Mundaú lagoon coast in front of Mutange, Pinheiro and Levada neighbourhoods. Inversion of the results, using analytical models, locates a sill-like source at ~400m depth and with a radius of ~0.8 km. Its depth would be compatible with re-activation of the Mutange fault system, possibly related to salt mining operations in the area. Further investigation is needed to better constrain the deformation source and to identify if the observed process was active before the analysed time span.